1. Field of the Invention
The present invention relates to a cleaning apparatus for cleaning the interior surface of a housing such as a cyclone furnace or boiler.
2. Description Of the Prior Art.
Coal fired boilers are commonly used in industry, Pulverized coal is fed into a boiler-through a cyclone burner which receives the pulverized coal from a feeder apparatus connected to the inlet of the cyclone burner. Initial burning of the coal occurs inside the cyclone burner with further burning occurring in the boiler. The boiler is typically a water-cooled horizontal cylinder. Air with a velocity of approximately 300 feet per second is admitted tangentially at the roof of the main barrel of the cyclone furnace and imparts a further whirling or centrifugal action to the coal particles. The combustible is burned at temperatures sufficiently high to melt the ash into a liquid slag, which forms a layer on the interior walls of the cyclone furnace. Incoming coal particles are thrown to the interior walls by centrifugal force and held in the slag. The coal particles are then scrubbed by the high-velocity tangential air.
The interior walls of the cyclone furnace accumulate slag deposits from the burning coal particles. The slag deposits may sometimes be as much as three feet thick. It is well known that some amount of slag is beneficial to the combustion although too much slag is detrimental. Therefore, the interior walls of the cyclone furnace need periodic cleaning to reduce the slag deposits to the desired thickness.
U.S. Pat. No. 4,673,661 to Nelson et al. discloses a semi-automated cyclone furnace cleaning apparatus requiring an operator to enter the cyclone furnace and rearrange or replace high pressure fluid nozzles in order to clean the various inside surfaces of the cyclone furnace.
U.S. Pat. No. 5,107,873 to Clinger discloses an apparatus similar to that described in the '661 patent. The apparatus disclosed in the '661 patent and the '873 patent includes a pair of diametrically opposed lances which are intended to move transversely to the longitudinal axis of the cyclone furnace and includes a nozzle arrangement to provide either a longitudinal spray or a transverse spray normal to the direction of the longitudinal spray.
It is desirable to have a furnace cleaning apparatus which provides maximum versatility in the cleaning operations of the cyclone furnace. It is further desirable to be able to adjust the angle of the fluid spray against the cyclone furnace walls. It is also desirable that the furnace cleaning apparatus be capable of simultaneously moving longitudinally in the cyclone furnace while rotating about the longitudinal axis of the cyclone furnace and further being capable of simultaneous reorientation of the direction of the nozzle spray.